Trimming mechanism



Feb. 13, 1934.

J. P. WEIS TRIMMING MECHANISM Filed NOV. 5, 1932 3 Sheets-Sheet 1 AT ORNYS.

Feb. 13, 1934. J was 1,946,558

TRIMMING- MECHANISM Filed Nov. 3, 1932 3 Sheets-Sheet 2 Feb. 13, 1934. J was 1,946,558

TRIMMING rmcimmsu Filed Nov. 5, 1952 s Sheets-Sheet s A TTORNE m'mmme John P. Wels, Nyack,

1,946,558 PATENT OFFICE MECHANISM N. Y., assignor to The Metropolitan Sewing Machine Corporation, Nyack, N. Y., a corporation of Delaware Application November 3,1932. Serial No. 640,937

22 Claims.

This invention relates to trimming mechanism for sewing machines, the object of the invention being to provide a simple, inexpensive trimming attachment which may be readily and easily attached and detached and the {stroke of which may be readily changed, whereby it is effective on various kinds of work.

A further object of the invention is the provision of an improved trimming attachment com- 0 prising a reciprocating cutter located at the side of the needle bar whereby it may co-operate with the throat plate and be operated by-the needle bar.

A further object of the invention is the provision of an improved reciprocating trimming means operated from the needle bar and, in which, the cutter may be readily adjusted for wide or narrow seams.

Another object of the invention is the provision of an improved trimmer attachment in which the cutter may be placed at either the right or left side of the needle or twin cutters used, one at each side of the needle, and which attachment may be applied to a sewing machine with a minimum of alterations thereto and may also be applied to the well-known Metropolitan sewing machines by the addition of a few simple inexpensive parts and will not, with ordinary care and attention get out of order.

Another object of the invention is the provision of an improved trimmer attachment which is so located and supported above the work plate that free passage of the work through the machine is permitted so that the machine can be used for seaming and trimming at times and at other times be used for plain sewing operations without the use of the trimmer.

Another object of the invention is the provision of an improved trimming. mechanism for all kinds of sewing and trimming operations on fabrics, leather and other materials and in the use of which a wide or narrow seam to suit the character of the work may be obtained and which is provided with means for changing the stroke or cutting movement of the trimming member thereby to adapt it for thick or thin materials.

In the drawings accompanying and forming a part of this specification, Fig. l is a front view of a well-known Metropolitan top and bottom rotary shaft sewing machine with this improved trimmer attachment applied thereto.

Fig. 2 is a left hand end view of the machin with the trimmer applied thereto.

Fig. 3 is a detail perspective of the trimmer parts.

Fig. 4 is a detail view of the trimmer knife operating lever link and knife guide and illustrates the rear side of the parts shown in Fig. 3.

Fig. 5 is a view similar to Fig. 2 in which the parts are adjusted for trimming heavy sweater goods and the like, this view showing a knife with a large cutting surface, and a ledger blade to co-operate therewith.

Fig. 6 is a perspective view of a throat plate with .a ledger blade suitable for use in the stitching and trimming of shoes and the like.

Fig. '7 is a perspective view of the holding means for the ledger blade for use in trimming fabrics and similar materials, and I Fig. 8 is a detail view partly in section on the line 8-8 of Fig. 5, looking in the direction of the arrow.

Similar characters of reference indicate corresponding parts in the several views.

- Before explaining'in detail the present improvement and mode of operation thereof, I desire to have it understood that the invention is not limited to the details of construction and arrangement-of parts illustrated in the accompanying drawings since the invention is capable of other embodiments, and the phraseology which I employ is for the purpose of description and not of limitation.

The sewing machine illustrated has the usual base 1, vertical trunk 2, top arm 3, head 4, cloth plate.5, throat plate 6, bottom rotary shaft 7, top rotary shaft 8, top crank shaft 10 and bottom crank shaft 11, to which connecting rods 9 are connected and bearings 12 and 13 for the top and bottom shafts.

The machine has the usual hand wheel 14, belt wheel 15, front bearing 16 for the top shaft, front bearing 17 for the bottom shaft, feed driving mechanism 18, feed lifting mechanism 19, looper mechanism 20 and driving means 21 for the looper mechanism.-

The needle bar 22 operates in bearings of the head 4 and is reciprocated by theneedle driving crank 23 and pitman 24 operated by the crank 23 through the crank pin 25 and connected at 26 to the clamp collar 27 carried by the needle bar. The needle bar carries the usual needle 28 that co-operates with the looper 29 for making the stitches.

The presser foot 30 carried by a presser bar 31 operating in the head 4, cooperates with the feed dog 32, carried by the feed bar 33 connected at the rear end as at 34 to the feed rocker frame 35 connected to the feed driving means 18. The presser foot bar 31 operates in a bearing 36 and is prevented from turning by a guide 37 moving in a slot in the head 4. This guide is clamped to the presser foot bar as at 38. On'the upper end of the bar rests a spring 39 to give downward pressure to the presser foot so that it will follow the feed motion at speed properly to feed the work through the machine.

The mechanism so far described comprises generally the well-known Metropolitan sewing machine and is thus briefly referred to for a clearer understanding of the improved trimming mechanism which will now be described.

The trimming mechanism comprises a reciprocating knife 40 rigidly secured as at 41 to a slide 45 by a screw 42, which has a long extending head so that it can be conveniently manipulated by the fingers as well as by a screw driver, and as the trimmer may be readily changed for some other instrumentality such as a punch, therefore, it projects to the left between the needle and presser bar for convenience. The knife has a cutting end as at 43 and guide end 44. A spacing block 46 is securedbetween the slide and the knife. The thickness of this block 46 may be varied to suit the required width of seam, that is; different thicknesses of blocks are provided for different widths of seams. The block is securely fastened to the slide 45 and this provides a very simple means of obtaining different widths of seams requiring merely the proper selection of block.

The knife is slotted at the top end for convenience in removal, replacement and vertical adjustment. The slide 45 is supported by a vertical plate 47 by means of gibs 48 and 49 which form a dove-tail slide-way for the vertical movement of the slide 45. The plate 47 is secured to the face of a bracket 50 which fits over the needle bar bushing 51 and the presser bar bushing 36, being clamped in position thereto by screws and this bracket 50 has a vertical adjustment on these two bushings, the plate 47 being connected thereto by screws 52, see Fig. 4.

The bracket 50 is provided with a rock shaft 53, see Fig. 8, to which is clamped an arm 54 by a screw 55. The forward end of the arm is bifur cated to receive the top end of a link 56, see Figs. 3 and 8, connected thereto by a shoulder screw 57.- The lower end 58 of this link 56 is pivotally connected by a screw 59 to the slide 45, see Fig. 4, and this screw 59 passes through a vertical slot 60 in the plate 47. The rock shaft 53 operates in a bearing 61 of the block, 50. One end of the rock shaft is provided with a head 62 terminating in an arm 63 upon which slides a sleeve 64. This sleeve is pivotally connected as at 65 to a stem of the needle bar clamp collar 27, shifted up and down by the needle bar. To prevent axial movement the other end of this part is provided with a stem and roller 66 operating in a vertical guideway 67, carried by the head 4.

From the foregoing it will be understood that as the needle bar moves up and down in the usual way, it carries with it the sleeve 64, thereby shifting it on the arm 63, and thus effecting a change in the angular position of the arm 63 so as to rock the shaft 53 to operate the arm 54 and the link 56, and thereby reciprocate the knife 40 which co-operates with a ledger blade, or the edge of a throat plate which may act as a ledger blade. To change the stroke or movement of the knife, that is, to give a high lift or a low lift to the knife, all that is necessary is to reverse the sleeve 64 on the stud 65. Figs. 2 and 5 illustrate how this is accomplished.

In Fig. 2, the parts are arranged to give a low lift or short stroke to the knife. In Fig. 5, the parts are arranged to give a high lift or long stroke to the knife.

In order to adapt a trimmer to a wide variety of uses, I prefer to employ at times a sharp edge 68 on the throat plate 6, see Fig. 3. For sewing and trimming bulky work such as sweater goods, clothing, or other materials, I employ a ledger blade 69 having a cutting edge at 70, see Fig. '7.

This blade is clamped in position by screws 71 to the vertical face 72 of a knife holder or bracket 73 slotted to receive the knife. This knife holder or bracket '73 is of right angle construction and has a supporting surface having a recess 74 for the reception of a block 75 secured to the cloth plate 5 by screws 77 passing through holes 76. Thus lateral adjustment of the bracket 73 is provided for different widths of seams by shifting the angle bracket knife holder 73 on the block '75, and thereby the cutting edge '70 of this knife 69 is adjusted into position to take the place of the edge 68 of the throat plate and to coact with the cutting edge 43 and guide 44 of the top knife 40.

For stitching leather shoes, I provide in the throat plate 6 a renewable and reversible needle hole piece- 78. The plate is slotted to receive a spring 79 acting against a fiatplate 80 that bears against the back face of the knife to give pres sure against the sharp edge of the needle hole piece as at 81 to cause a keen shearing action. This sidewise pressure is a well-known necessity for leather stitching and trimming since the vertical knife for such work is preferably very thin and this side pressure prevents its springing away. A filler block 82 is also provided in front of the plate 80 in a slightly overlapping position to keep the parts in working position and prevent the work catching on the front end of the plate 80.

In the present improvement the stroke of the needle may be 1" or 2", yet the knife stroke may be but to depending upon the hook-up of the parts and the angular position of the arm 63. By removing the plate 47 and link 46, the machine is quickly cleared of the trimmer parts adjacent to the needle and by adding or substituting a punch for the cutter and having it cooperate with a circular shaped die opening in the throat plate, the attachment can 'also be used for perforating leather or other materials.

In the present improved attachment, it will be seen that the top trimming knife has, by reason of its connection with the needle bar, a different movement than that of the needle bar for when the sleeve 64 is near the top of the arm 63, the movement of the knife is much slower than when this sleeve moves down nearer to the rock shaft 53 so that its cutting power varies because of this differential movement. Consequently, the thickest work is out while the sleeve 64 is near the top of the arm where it has the greatest leverage.

Needle bars of sewing machines must have a movement considerably greater than what is required for operating the trimmer and in those cases where it has been attempted to operate a trimmer from a needle bar with the trimmer having the same stroke as the needle bar, the result has been unsatisfactory for the best cutting condition is obtained by having a knife reciprocating just sufficient to accommodate the thickest portion of the goods that the machine is called upon to handle. For instance, garments made of silk or other woven fabrics not much thicker than a visiting card and having seams that add several more thicknesses, require that the knife must travel about 34;" while, in that class of material such as sweaters where the thickness of the material is from A" to the trimmer would have to have a movement of substantially that amount and experience has shown that a knife having movement is sufilcient in extreme cases. Consequently, in the present improvement, the knife has a movement of one-fifth to one-half of the needle movement, this being obtained by the reversal of the sleeve 64.

It is to be understood that, by describing in detail herein any particular form, structure or arrangement, it is not intended to limit the invention beyond the terms of the several claims or the requirements of the prior art.

Having thus explained the nature of my said invention and described a way of constructing and using the same, although without attempting to set forth all of the forms in which it maybe made or all of the modes of its use, I claim:

1. A trimming attachment for sewing machines having a needle barrand comprising a reciprocating cutter, a connection between said cutter and needle bar whereby the cutter is operated by the needle bar, said connection including a vertically reciprocating slide for varying the cutting power of the cutter during the operation of the needle bar.

2. A trimming attachment for sewing machines having a needle bar and comprising a reciprocating cutter pivotally connected to and positively operated by the needle bar and including means for varying the length of the stroke of the cutter.

3. A trimming attachment for sewing machines having a needle bar and comprising a reciprocating cutter connected to and operated by the needle bar and including means for varying the stroke of the cutter, said means comprising a member reversible relative to the needle bar.

4. A trimming attachment, for sewing machines having a needle bar and comprising a reciprocating cutter, a slide carrying it, a rock shaft, linkage connecting the rock shaft and slide, and an arm connected with the rock shaft and needle bar.

5. A trimming attachment for sewing machines having a needle bar and comprising a reciprocating cutter, a slide carrying it, a rock shaft, linkage connecting the rock shaft and slide, and an arm connected with the rock shaft and needle bar and including a member slidably carried by said arm.

6. A trimming attachment for sewing machines having a needle bar and comprising a reciprocating cutter, a slide carrying it, a rock shaft, linkage connecting the rock shaft and slide, and an arm connected with the rock shaft and needle bar and including a member slidably carried by said arm and reversible relative to the needle bar.

'7. A trimming attachment for sewing machines having a needle and presser foot bars, abracket clamped in position relative thereto, a reciprocating instrumentality carried by the bracket, and means pivotallyconnected withtheneedlebarand with said instrumentality for reciprocating said instrumentality and including means for varying the stroke thereof to give a shorter or longer movement.

8. A trimming attachment for sewing machines having a needle and presser foot bars, a bracket clamped in position relative thereto, a reciprocating instrumentality carried by the bracket, and means connected with the needle bar for reciprocating said instrumentality and including a part reversible relative to the needle bar whereby the stroke of the instrumentality may be varied.

9. In a sewing machine having needle and presser foot bars, a bracket clamped in position relative thereto, a reciprocating instrumentality carried thereby, a rock shaft connected with the reciprocating instrumentality and connected with the needle bar for reciprocating said instrumentality.

10. In a sewing machine having needle and presser foot bars, a bracket clamped in position relative thereto, a reciprocating instrumentality carried thereby, and a rock shaft connected with the reciprocating instrumentality and connected with the needle bar for reciprocating said instrumentality, and including a sleeve reversible relative to the needle bar whereby the stroke of the instrumentality may be varied.

11. A trimming attachment for sewing machines having a needle bar and comprising a reciprocating instrumentality operative during the reciprocation of the needle, a slide carrying it, means for vertically shifting said slide and comprising an arm pivotally connected with the needle bar and slide.

12. A trimming attachment for sewing machines having a needle bar and comprising a reciprocating instrumentality, a slide carrying it, means for vertically shifting said slide and comprising an arm and a sleeve slidable on said arm and connected with the needle bar.

13. A trimming attachment for sewing machines having a needle bar and comprising a reciprocating instrumentality, a slide carrying it, means for vertically shifting said slide and comprising an arm and a sleeve slidable on said am and connected with the needle bar, said sleeve being reversible relative to the needle bar thereby to vary the stroke of the instrumentality.

14. A trimming attachment for sewing machines having a needle and presser bars, a bracket clamped in position relative thereto, a slide supported by said bracket, a vertically reciprocating cutter carried by said slide, a rock shaft, linkage connection between said slide and rock shaft, an arm connected with the rock shaft, a sleeve slidable on the arm and-pivotally connected with the needle bar and reversible relative to said needle bar thereby to vary the stroke of the cutter.

15. A trimming attachment for sewing machines having a needle bar and comprising a reciprocating cutter,- a connection between said cutter and needle bar whereby the cutter is operated by the needle bar, said connection comprising a vertically extending arm and a member slidable thereon and connected with the needle bar, and a co-operating cutting member carried adjacent to the throat plate of the machine, said reciprocating cutter having a movement less than that of the needle bar.

16. A trimming attachment for sewing machines having a needle bar and comprising a reciprocating cutter connected to and operated by the needle bar, said connection including an 130 arm and a member slidable thereon and connected to the needle bar, and a co-operating cutting member carried adjacent to the throat plate of the machine and adjustable relative thereto.

17. A trimming attachment for sewing ma; 135 chines having a needle bar and comprising a reciprocating cutter pivotally connected to and positively operated by the needle bar and including means for varying the stroke of the cutter, and co-operating cutting means carried adjacent to the throat plate of the machine.

18. A trimming attachment for sewing machines having a needle bar and comprising a reciprocating cutter connected to and operated by the needle bar and including means for vary- 14.5 ing the stroke of the cutter and comprising an arm and a member slidable relative thereto, and co-operating cutting means carried adjacent to the throat plate 01. the machine and comprising an adjustable cutter.

19. A trimming attachment for sewing machines having needle and presser toot bars, a

a slide carried thereby, a reciprocating cutter carried by said slide, an interchangeable means between the cutter and slide for adjusting the cutter for various widths of seams, and means operated by the needle bar for reciprocating said cutter.

21. A trimming attachment for sewing machines having a needle bar and comprising 9.

reciprocating cutter, means for reciprocating the cutter and including an arm extending in a plane parallel to a plane of the needle bar and located at an angle thereto, a member pivotally connected to the needle bar and shiitably connected with the arm wherebythe movement 01 the needle bar will vary the angular position of the arm relative to the needle bar and thereby reciprocate the cutter.

22. A trimming attachment for sewing machines having a needle bar and comprising a reciprocating cutter, means for reciprocating the cutter and including an arm extending in a plane parallel to a plane of the needle bar and located at an angle thereto, a reversible member pivotally connected to the needle bar and shiftably connected with the arm whereby the movement 01' the needle bar will vary the angular position of the arm relative to the needle bar and thereby reciprocate the cutter.

JOHN P. WEIS. 

